This invention relates to microscopes and more particularly concerns a microscope for examining a specimen isolated in a gas-tight chamber.
It is known to install microscopes in gas-tight chambers for the examination of specimens which must not come into contact with ambient atmosphere. Such arrangements are employed, inter alia in investigations involving alpha-emitters, toxic materials, materials which are hazardous to health, substances kept under specific atmospheric conditions and investigations of the effects of various atmospheric influences on living organisms. A further field of application arises in the testing of wafers in the electronics industry where the wafers must not be contaminated by dust.
Microscopes which are suitable for installation, upright or inverted, in a gas-tight chamber are arranged so that the viewing and/or recording elements are separated from gas-tight chamber by a small glass plate in a mounting; such elements include viewing eyepieces, mounting units for mounting a photographic or television camera, and light sources. Other manual operations, for example, moving the specimen in an x--y plane and focussing, are carried out through two gloveports through which extend gas-tight gloves. Additional ports may be provided to enable air-locks or other chambers to be connected to the chamber, for example, to introduce a prepared specimen without exposing it to ambient atmosphere.
Such arrangements cause problems because the body of the microscope, which contains the image-forming components, is connected in a complicated manner to a support. The support is mounted on a base and may contain a drive assembly for moving the specimen in an x--y plane, and for focussing.
Sealing by the installation of a plate on the body of the microscope is an expensive operation. It is necessary to seal off the viewing eyepieces and any camera mounting unit from the gas-tight chamber. The known sealing plates for effecting such sealing are bent into particular shapes in an operation which requires a high degree of precision and hence are expensive.